For kids, Saturday morning is sacred. You wake up maybe around 7:30 a.m. and you head downstairs in your pajamas. You find your favorite cereal, pour it in your special giant bowl and add the milk.

In the case of “Good Morning Good Morning,” John Lennon, the song’s chief writer for The Beatles, didn’t explain that it might have come from his own deep-seated frustrations with his daily life. But ...